1. Field of the Invention
The present invention relates to a process and an apparatus used in the process for encapsulating a flat panel display device, and more particularly to, an apparatus for encapsulating a display panel capable of hermetically sealing a gap of the display panel and improving strength of the display panel, and a method of manufacturing an organic light emitting display device.
2. Description of The Related Art
An organic light emitting display device is one of flat panel displays, and generally includes two electrodes facing each other and spaced apart from each other, and an organic light emitting layer disposed between these two electrodes. When a voltage is applied to both of these two electrodes, electrons injected into one electrode and holes injected into the other electrode are combined in the organic light emitting layer. Here, molecules of the light emitting layer are excited by their combination, and then releases energy as the light, the energy being emitted while returning to a ground state. The organic light emitting display device has excellent visibility, and may be manufactured in a light-weight and thin configuration, and may be driven by a lower voltage, therefore, an increasing public attention has been attracted as the next-generation display device.
The organic light emitting display, however, has a problem that it may be easily deteriorated when the moisture is penetrated into organic matters constituting the organic light emitting layer.
In order to solve these and other related problems regarding the organic light emitting display device, a moisture-absorbing agent may be installed inside of the display device. The method using a moisture-absorbing agent however has a limitation to remove the moisture penetrated into the organic light emitting diode, and it is difficult to mass produce the display device due to the low durability and reliability of the display device. In addition, a method where a moisture-absorbing agent is mounted in the form of powder is complicated, and the costs of materials and processes are therefore increased, thickness of the display device is increased, and it is difficult to apply to the top emission type device. Also, a method of coating an encapsulation substrate with a moisture-absorbing agent has problems that outgassing phenomenon is caused during the sintering process, and therefore an adhesive force between a seal and a substrate may be undesirably decreased and thus the organic light emitting diode may be easily exposed to moisture.
In order to solve the above stated problems regarding the organic light emitting display device, a method of forming a side wall of a frit to seal an organic light emitting diode may be used.
The organic light emitting display device that is coated and sealed with a frit, however, still has limitations in the aspect of completely preventing the penetration of moisture. In particular, because the frit may be easily broken when external impacts are applied to the frit, stress converges to an adhesion surface of the frit and the substrate, and the frit and the encapsulation substrate, therefore, cracks may be generated from the adhesion surface, and be spread into the entire substrate.